For the pork sirloin:
Prepare the coals on the braai to a medium heat. Preheat the oven or air fryer to 180 °C. In a bowl, mix together the olive oil, garlic, smoked paprika, ground cumin, chilli flakes, dried oregano, salt and pepper. Rub the mixture all over the pork sirloin and set aside. Place the pork sirloin on the braai and cook for 20–30 minutes, turning regularly to prevent burning, until the internal temperature reaches 63 °C. Remove from the heat and rest for 5 minutes before slicing.
For the chimichurri:
In another bowl, combine the parsley, coriander, oregano, garlic, red onion, red chilli, red wine vinegar, lime juice, zest and olive oil. Season with salt and pepper and mix well. Set aside.
To serve:
Slice the pork sirloin thinly and arrange on a serving platter. Spoon over the chimichurri and serve.